Computer graphics processing and selective visual display system – Plural physical display element control system – Display elements arranged in matrix
Reexamination Certificate
1999-04-21
2002-08-06
Chow, Dennis-Doon (Department: 2775)
Computer graphics processing and selective visual display system
Plural physical display element control system
Display elements arranged in matrix
C345S096000, C345S087000, C345S100000
Reexamination Certificate
active
06429842
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a liquid crystal display, and more particularly to a thin film transistor(TFT) pixel arrangement embodying a dot inversion driving with a line inversion driving.
Liquid crystal displays (LCDs) is a next-generation display device and an immense market to LCDs is prospected to be made. LCD technology has been developed into TFT-LCDs from TN-LCDs and the display performance of LCDs is improved. A TFT-LCD drives a pixel electrode with a TFT, which has a TFT pixel arrangement as shown in FIG.
1
. In the prior TFT-LCD
100
, TFTs are disposed at the cross points of data lines D
1
-Dn and gate lines G
1
-Gm and are arranged in the upside of the respective gate lines G
1
-Gm.
So as to prevent deterioration of liquid crystal due to a DC voltage, a data inversion driving method is used to drive the TFT-LCD. The data inversion method for preventing deterioration of LC is a method for driving a LCD by alternatively applying a positive(+) data signal and a negative(−) data signal on the basis of one pixel every fields. There are a field inversion driving method, a line inversion driving method, a column inversion driving method and a dot inversion driving method as the data inversion driving method.
The field inversion driving method is shown in
FIG. 2
a
and FIG.
2
B. On the basis of one pixel, positive(+) data signals are supplied to pixel electrodes in a first field as shown in
FIG. 2
a
and negative(−) data signals are supplied to the pixel electrodes in a second field as shown in
FIG. 2
b.
However, the field inversion driving method has a disadvantage that asymmetry between the positive pixel voltage and the negative pixel voltage is caused due to capacitive coupling between a gate and a source/drain of a TFT so a flicker is occurred on the entire picture screen of a LCD.
The line inversion driving method is shown in FIG.
3
. Positive(+) data signals and negative(−) data signals are alternatively applied to the pixel electrodes along the gate lines G
1
-Gm. That is, the polarity of the voltage applied to the pixels of the odd gate lines G
1
, G
3
, G
5
, . . . has the opposite polarity of the voltage applied to the pixels of the even gate lines G
2
, G
2
, G
6
, . . . so that the flicker caused between adjacent two pixels in the column direction is offset. However, the line inversion driving method has a disadvantage that the data signals having the same polarity are applied between adjacent two pixels in the row direction so that horizontal crosstalk remains as usual.
The column inversion driving method is shown in FIG.
4
. Positive(+) data signals and negative(−) data signals are alternatively applied to the pixel electrode along the data lines D
1
-Dn That is, the polarity of the voltage applied to the pixels of the odd data lines D
1
, D
3
, D
5
, . . . has the opposite polarity of the voltage applied to the pixel of the even data lines D
2
, D
4
, D
6
, . . . so that the flicker caused between adjacent two pixels in the row direction is offset. However, the column inversion driving method has a disadvantage that the data signals having the same polarity are applied between adjacent two pixels in the column direction so that vertical crosstalk remains as usual.
The dot inversion driving method is shown in
FIG. 5
, which is in combination of the line inversion driving method and the column inversion driving method. The voltages having different polarities are provided to adjacent two pixels in the row and column directions, respectively so that the flicker caused between adjacent two pixels in the row and the column directions.
However, the dot inversion driving method prevents the flicker to improve the picture quality of TFT-LCDs but the driver IC for the dot inversion driving has a complicate construction and is difficult to drive and the power consumption is large.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a TFT pixel arrangement of a TFT-LCD which can embody a dot inversion driving with a line inversion driving by arranging TFTS with a zig-zag type along gate lines.
It is another object of the present invention to provide a TFT pixel arrangement of a TFT-LCD capable of embodying a dot inversion driving without modification of a driving IC.
It is still another object of the present invention to provide a TFT pixel arrangement of a TFT-LCD capable of solving the crosstalk problem in a line inversion driving method to improve the picture quality.
It is an aspect of the present invention to provide a TFT-LCD comprising: a plurality of data lines being spaced with each other; a plurality of gate lines being spaced with each other and being crossed with the gate lines; a plurality of thin film transistors (TFTs); and a plurality of pixel electrodes connected to the plurality of TFTs, respectively; wherein TFTs of the plurality of TFTs which are connected to odd data lines of the plurality of data lines, are disposed in the upside of the gate lines and the TFTs of the plurality of TFTs which are connected to the even data lines of the plurality of data lines, are disposed on the downside of the gate lines, thereby being disposed with a zig-zag form; and wherein when odd gate lines of the plurality of gate lines are driven, the first data signals having the first polarity are provided to the plurality of data lines and when even data lines are driven, the second data signals having the second polarity are provided to the plurality of data lines.
In the preferred embodiment, the first data signals are positive data signals and the second data signals are negative data signals. Otherwise, the first data signals are negative data signals and the second data signals are positive data signals.
In the preferred embodiment, the data signals having different polarities are respectively applied to the data lines corresponding to the odd gate lines of the plurality of gate lines and to the data lines corresponding to the even gate lines of the plurality of gate lines respectively, thereby applying the data signals having different polarities between adjacent two pixels.
REFERENCES:
patent: 4639720 (1987-01-01), Rympalski et al.
patent: 4651148 (1987-03-01), Takeda et al.
patent: 5151689 (1992-09-01), Kabuto et al.
patent: 5159476 (1992-10-01), Hayashi
patent: 5253091 (1993-10-01), Kimura et al.
patent: 5453857 (1995-09-01), Takahara
patent: 5526014 (1996-06-01), Shiba et al.
patent: 5581318 (1996-12-01), Shiratori
patent: 5648793 (1997-07-01), Chen
patent: 5691788 (1997-11-01), Kim
patent: 5739805 (1998-04-01), Dingwall
patent: 5959599 (1999-09-01), Hirakata
patent: 6040813 (2000-03-01), Takubo
patent: 06242448 (1994-09-01), None
Lee Keun Soo
Shin Jae Hak
Chow Dennis-Doon
Hyundai Display Technology Inc.
Nelson Alecia
LandOfFree
Liquid crystal display does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Liquid crystal display, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Liquid crystal display will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2894249